Author Topic: Car Audio (Read 521 times)

Lazer · « **on:** July 11, 2004, 02:56:23 PM »

Here is a question for anyone good with car audio...

I hardwired my own CD player into a BMW, because I didn't feel like paying an unreal amount for a wireharness, and now I seem to have static sound in my speakers, ONLY when the car is on/in motion.

If you play music with just car power on, and no engine running... it sounds fine.

Any ideas??

Lizking · « **Reply #1 on:** July 11, 2004, 03:02:13 PM »

Yeah, Don't do your own wiring.

NUKE · « **Reply #2 on:** July 11, 2004, 03:03:59 PM »

Sounds like you have ignition noise. You need to check that the head unit has a solid ground to begin with. Use an Ohm meter to check that the ground is good.

I have solved many cases of motor noise, it's a step by step elimination process, but begin by checking that ground.

Do you have a seperate amp or amplified speakers?

capt. apathy · « **Reply #3 on:** July 11, 2004, 03:05:44 PM »

did you run the power for the CD player through the radio circuit or it's own? I believe the radio circuits are insulated from feedback from your ignition system, while others aren't.

it was explained to me a few years ago but I really wasn't paying much attention at the time, hopefully someone with more usable knowledge will reply.

Lazer · « **Reply #4 on:** July 11, 2004, 03:08:26 PM »

No amp.. I don't even have car speakers in ATM.. they are in the mail.

I hooked up a pair for Awia home audio...

Where should I check for the ground connection?

NUKE · « **Reply #5 on:** July 11, 2004, 03:25:32 PM »

You need an OHM meter. Then pull the radio out of the dash, test between the radio chassis and a good, metal section of the car....a good spot is the door hinges/bolts/screws in running boards...etc. You should read very close to 0 ohms resistance.

If you don't have a meter, get some wire and attach it to the radio chassis at the back brace, and then connect ( touch) the other end to a good metal section of the interior or dash while the car is running. Test different areas and listen for the noise as you go. Also, move the radio in and out to see if the noise increases or decreases.

It's almost always a ground problem with a head unit and no amp. Very rarely , it can be the head unit itself.

Also, if the car is in a garage, pull it outside. Ignition noise can be a lot worst from an enclosed area.

Lazer · « **Reply #6 on:** July 11, 2004, 03:28:12 PM »

How should I fix it?

NUKE · « **Reply #7 on:** July 11, 2004, 03:32:02 PM »

Quote

Originally posted by Lazer
How should I fix it?

make sure it has a good ground, pretty much in a nutshell. If you still have the noise and do not have the experience or patience to trouble-shoot the problem, you need to take it to an installer that knows what they are doing.

Lazer · « **Reply #8 on:** July 11, 2004, 03:32:22 PM »

I think I got it now.. Thanks NUKE/Apathy

Gunslinger · « **Reply #9 on:** July 11, 2004, 03:33:01 PM »

they make good ground filters that are less than $20. All they do is filter out all that noise to ground.

Next time use a wiring harness. They arent that expensive and they save you ALOT of headaches further down the road.

NUKE · « **Reply #10 on:** July 11, 2004, 03:37:28 PM »

Quote

Originally posted by Lazer
I think I got it now.. Thanks NUKE/Apathy

if you want, email me ( profile)

I'll call you and help you if you would like.

Lazer · « **Reply #11 on:** July 11, 2004, 03:52:10 PM »

Im restoring an 87' BMW, and it seems difficult to find a wire harness for it.

I know the benefit of a wire harness, have a little newer BMW and I could find that harness, and believe me, it was much easier than this is...

NUTTZ · « **Reply #12 on:** July 11, 2004, 05:25:55 PM »

also the antenna can pick up engine frequiency, install a good antenna.

NUTTZ

NUKE · « **Reply #13 on:** July 11, 2004, 05:37:31 PM »

I just thought of this:

Whatever you connected from the car's harness to the radio's ground wire.... cut that connection, leaving the antenna plugged in. Listen. Is the noise gone?

DREDIOCK · « **Reply #14 on:** July 11, 2004, 05:40:44 PM »

I know in the old days when I was into that sort of thing all we usually hadta do to cure it was to spend a couple extra bucks on Silicone sparkpplug and coil wires.

Worked every time